In the medical and related diagnostic and testing fields, it is often required to take small samples of blood from a subject for the purpose of testing or analysing the blood. A common way of achieving this is by using a small needle to pierce the skin at a location where blood vessels are close to the surface. The combination of a needle and its holder is commonly known as a lancet. In order to avoid infection and contamination, lancets are preferably intended for single use and are disposable. They must therefore be compact to allow users to carry multiple lancets on their person, and cheap to manufacture.
A number of disposable lancet devices are currently on the market. These include the Unistik™ manufactured and marketed by Owen Mumford Ltd (Woodstock, UK). The current designs comprise a moulded plastics casing within which is mounted a short, spring-loaded needle. A trigger is formed in the casing which, when depressed, releases the lancet causing the tip to be fired out through an opening in the casing. Some of the current designs require a user to preload or cock the spring prior to firing. In other designs, the lancet devices are supplied already cocked. It is also generally necessary for users to remove a cap from the front of the device or the needle tip prior to firing. Users must therefore perform at least two steps, and sometimes three, in order to perform the blood sampling procedure.
There exists a desire for a lancet device or apparatus which is simpler to operate than current designs. Of course, any improved design must meet high standards with regard to manufacturing costs. It must also be reliable, ensuring that lancet devices are provided to users in an operable condition.